Add basil, creme fraiche, olive oil, lime juice and salt to a food processor or blender and blend until nice and smooth.
Heat the grill or a cast iron skillet over medium high heat until it starts smoking.
Generously salt and pepper steak on both sides (make sure the stake is not cold, take it out of the fridge for at least one hour before grilling).
Wash and dry tomatoes.
Add a tiny bit of avocado oil (or other high smoke point fat) to pan only if using, no need to oil the grill and carefully add the steak. Grill for 4-5 minutes on one side and 2-3 minutes on the other depending on thickness and desired doneness (in my case I ended up with a medium after 5 and 3 minutes, just like I like it).
Once meat is done, remove from grill/pan and let rest on a cutting board without cutting into it!
If cooking on the stovetop with a pan, while steak is grilling in pan cut the corn kernels off the cooked ear and peel and slice the avocado. If grilling, no need to remove corn kernels.
Arrange avocado on plate.
Add another tiny splash of oil into the pan only if using and put corn and tomatoes into pan. Or place whole corn and tomatoes on grill for 1 minute max on two sides and place on plate.